Directive antenna



June 26, 19340 KQQMANS 1,964,189

DIRECT IVE ANTENNA Filed Sept. 11, 1928 ill A/ /foa 1 107 i M M PatentedJune 26, 1934 UNiTE STATES PATENT FFICE DIRECTIVE ANTENNA NicclaasKoomans, The Hague, Netherlands, as-

signor to Radio Corporation of America, New

York, N. Y.

11 Claims.

This invention has reference to directive aerial systems in which theuniformity in phase of the radiant parts is endeavoured to be ensured.

These systems may be efiiciently composed with the aid of symmetricallyarranged feeders having connected to them doublets spaced at one wavelength or a half wave length apart, the feeders being in the latter casealternately crossed.

It can be established theoretically:

1. That in this manner all the doublets are in the same phase;

2. That this is not detrimentally influenced by reflections in thetapping points.

3. That all the doublets receive an equal quantity of current, the lastone consequently as much as the first one, when the feeder has nodamping. The latter has therefore to be constructed so as to have alarge surface.

A uniphasal straight radiating aerial wire is a directive antennaadapted for transmission as well as for reception. The more wave lengthsit is long, the greater is the directive efiect.

According to the invention such radiating aerial can be composed in aparticularly efficient and simple manner by building it up from doubletswhich are branched off a feeder. If a directive aerial system is wantedwhich has a greater directional effect, because of a beam being alsoformed in another plane, an aerial system according to the invention canbe constructed which comprises two or more similar aerials spaced at ahalf wave length apart, the conductors which are branched off thefeeders, having doublets, alternately crossed, connected to them.

The invention will be more clearly understood by reference to theaccompanying drawing in which Figure 1 shows a feeder, having connectedto it 40 doublets, alternately crossed, which are spaced at a half wavelength apart.

Figure 2 shows a symmetrical feeder to which branch conductors b areconnected so as to be spaced at a wave length apart.

These branch conductors have the doublets 0 connected to them in themanner shown in the figure by arrows.

In this manner a uniphasal aerial I, according to the invention, isformed.

If the branch conductors b are lengthened as shown in Figure 2 and ifdoublets d are connected to the said branch conductors so as to becrossed, a second uniphasal aerial II is produced which is at a halfwave length spaced apart from the first one.

(Cl. i)33) The said crossing can be effected either by arranging thedoublets (2 so as to be crossed or by crossing the branch conductors.

If the branch conductors are still further lengthened, it is possible toprovide still more uniphasal aerials which are alternately crossed and astill greater number of aerials which are parallel to each other isobtained.

The arrangement, shown in Figure 2 may be provided in any desireddirection. As a rule the aerials will be arranged so as to be eitherhorizontal or vertical.

In the foregoing, uniphasal aerials are referred to and they areillustrated to be situated in a straight line. However it is evidentthat slight differences do not cause the arrangement to depart from thescope of the invention. These differences may be of different nature,for exam-- ple the successive doublets may not be situated in a straightl'ne or spacings may be provided by leaving out a doub"et now and thenor by making the doublets slightly shorter.

Referring to Figure 2, a uniphasal aerial according to the invention isformed by branching conductors which are spaced at a wave length apartof a feeder and connecting to them doublets of twice a half wave length.

The same result may be obtained by conductors branched off the feederspaced at a half wave length apart and alternately crossed, and byconnecting to these branching conductors doublets of twice a quarterwave length.

The invention is adapted for transmission as well as for the receptionantennas.

What I claim is:

1. In a communication system for transmitting or conveying intelligencefrom one geographically situated point to another by means of propagatedelectromagnetic wave energy derived from the flow of h gh frequencyundulatory electrica currents operated upon in accordance with theintelligence to be transmitted. di ective antenna system comprising atwo wire conducting transmission line the wires of which are relativelyclose together and being crossed at points onehalf wave length apart,and linear radiators connected to the two wire line and arranged normaly thereto at points intermediate the crossing points of the two wireline.

2. In a communication system for transmitting or conveying intelligencefrom one geographically situated point to another by means of propagatedelectromagnetic wave energy derived from the flow of high frequencyundulatory electrical currents operated upon in accordance with theintelligence to be transmitted, a directive antenna system comprising arelatively closely spaced two conductor transmission line, eachconductor thereof being continuously conductive throughout its length,and linear conductors arranged normally to the line and spaced apart awhole multiple of a half wave length on said line and connected to theline whereby, by virtue of their spacing, each of said linear conductorsis excited in predetermined phase relationship and whereby the radiantaction of all of the linear conductors is highly directional.

3. In a communication system for transmitting or conveying intelligencefrom one geographically situated point to another by means of propagatedelectromagnetic wave energy derived from the flow of high frequencyundulatory electrical currents operated upon in accordance with theintelligence to be transmitted, a directive antenna system comprising arelatively closely spaced unbroken two-conductor transmission line, theconductors of which are conductive throughout their length, and linearconductors arranged normally to said line and directly connected theretofor obtaining a predetermined phase relationship spaced successively ahalf wave length apart in the direction of the line, said linearconductors by virtue of their spacing, having an overall high- 1ydirectional radiant characteristic.

4. In a communication system for transmitting or conveying intelligencefrom one geographically situated point to another by means of propagatedelectromagnetic wave energy derived from the flow of high frequencyundulatory electrical currents operated upon in accordance with theintelligence to be transmitted, a directive antenna system comprising amulti-conductor transmission line crossed at point one-half wave lengthapart, and linear radiators one-half wave length apart, connected to theline at points intermediate the crossing points of the line whereby, byvirtue of the spacing of the radiators, the entire system is given ahighly directional radiant characteristic.

5. In a communication system for transmitting or conveying intelligencefrom one geographically situated point to another by means of propagatedelectromagnetic wave energy derived from the flow of high frequencyundulatory electrical currents operated upon in accordance with theintelligence to be transmitted, a directive antenna system comprising asubstantially straight two wire transmissionline, a plurality of twowire branch lines connected to and arranged normally of saidtransmission line, and linear radiators directly connected to said twowire branch lines said branched lines being crossed at points one halfwave length apart.

6. In a communication system for transmitting or conveying intelligencefrom one geographically situated point to another by means of propagatedelectromagnetic wave energy derived from the flow of high frequencyundulatory electrical currents operated upon in accordance with theintelligence to be transmitted, a directive antenna system comprising asubstantially straight two wire transmission line, a plurality of twowire branch lines connected to and arranged normally of saidtransmission line, and linear radiators connected to said two wirebranch lines, successive radiators on said branch lines being spacedone-half wave length apart.

7. In a communication system for transmitting or conveying intelligencefrom one geographically situated point to another by means of propagatedelectromagnetic wave energy derived from the flow of high frequencyundulatory electrical currents operated upon in accordance with theintelligence to be transmitted, a directive antenna system comprising aclosely spaced two wire transmission line, closely spaced two wirebranch lines spaced apart on said transmission line a multiple of a wavelength and arranged normally to said transmission line, and linearradiators arranged normally to said branch transmission lines, andspaced apart thereon one-half wave length, said branch lines beingcrossed at points one-half wave length apart and intermediate saidradiators whereby all of said radiators carry high frequency currents ofpredetermined phase relationship giving the entire system a highlydirectional characteristic.

8. A directive antenna system comprising a two wire conducingtransmission line the wires of which are relatively close together andcrossed at points substantially one half wave length apart, and linearradiators connected to the wire line, said linear radiators being spacedapart a whole multiple of a half wave length.

9. A directive antenna system comprising a two wire conductingtransmission line the wires of which are relatively close together andcrossed at points substantially one half wave length apart, and linearradiators connected to the wire line and arranged normally thereto atpoints intermediate the crossing points of the two wire line,

said linear radiators being spaced apart a Whole multiple of a half wavelength.

10. A directive antenna system comprising a substantially straight twowire transmission line, a plurality of two wire branch lines connectedto and arranged normally of said transmission line and linear radiatorsconnected to said two wire branch lines, successive radiators of saidbranch lines being spaced one half wave length apart, and said branchlines being crossed between successive radiators.

11. In a communication system for transmitting or conveying intelligencefrom one geographically situated point to another by means of propagatedelectromagnetic energy derived from the flow of high frequencyundulatory electrical currents operated upon by the intelligence to betransmitted, a directive antenna system comprising a closely spaced twoconductor transmission line, and linear radiators arranged normally tosaid line and connected thereto in such manner as to obtain apredetermined phase relationship and spaced successively a half wavelength apart in the direction of the line, said linear radiators byvirtue of their spacing having an overall directive characteristic.

NICOLAAS KOOMANS.

